The differences in the way of fixing the period of
Easter did not indeed disappear after the Council of Nicea.
Alexandria and Rome could not agree, either because one of the two
Churches neglected to make the calculation for Easter, or because the
other considered it inaccurate. It is a fact, proved by the
ancient Easter table of the Roman Church, that the cycle of eighty-four
years continued to be used at Rome as before. Now this cycle
differed in many ways from the Alexandrian, and did not always agree
with it about the period for Easter—in fact (a), the Romans used
quite another method from the Alexandrians; they calculated from the
epact, and began from the feria prima of January. (b.) The
Romans were mistaken in placing the full moon a little too soon; whilst
the Alexandrians placed it a little too late. (c.) At Rome the
equinox was supposed to fall on March 18th; whilst the Alexandrians
placed it on March 21st. (d.) Finally, the Romans differed in
this from the Greeks also; they did not celebrate Easter the next day
when the full moon fell on the Saturday.

Even the year following the Council of Nicea—that
is, in 326—as well as in the years 330, 333, 340, 341, 343, the
Latins celebrated Easter on a different day from the
Alexandrians. In order to put an end to this misunderstanding,
the Synod of Sardica in 343, as we learn from the newly discovered
festival letters of S. Athanasius, took up again the question of
Easter, and brought the two parties (Alexandrians and Romans) to
regulate, by means of mutual concessions, a common day for Easter for
the next fifty years. This compromise, after a few years, was not
observed. The troubles excited by the Arian heresy, and the
division which it caused between the East and the West, prevented the
decree of Sardica from being put into execution; therefore the Emperor
Theodosius the Great, after the re-establishment of peace in the
Church, found himself obliged to take fresh steps for obtaining a
complete uniformity in the manner of celebrating Easter. In 387,
the Romans having kept Easter on March 21st, the Alexandrians did not
do so for five weeks later—that is to say, till April
25th—because with the Alexandrians the equinox was not till March
21st. The Emperor Theodosius the Great then asked Theophilus,
Bishop of Alexandria for an explanation of the difference. The
bishop responded to the Emperor’s desire, and drew up a
chronological table of the Easter festivals, based upon the principles
acknowledged by the Church of Alexandria. Unfortunately, we now
possess only the prologue of his work.

56Upon an invitation
from Rome, S. Ambrose also mentioned the period of this same Easter in
387, in his letter to the bishops of Æmilia, and he sides with the
Alexandrian computation. Cyril of Alexandria abridged the paschal
table of his uncle Theophilus, and fixed the time for the ninety-five
following Easters—that is, from 436 to 531 after Christ.
Besides this Cyril showed, in a letter to the Pope, what was
defective in the Latin calculation; and this demonstration was taken up
again, some time after, by order of the Emperor, by Paschasinus, Bishop
of Lilybæum and Proterius of Alexandria, in a letter written by
them to Pope Leo I. In consequence of these communications, Pope
Leo often gave the preference to the Alexandrian computation, instead
of that of the Church of Rome. At the same time also was
generally established, the opinion so little entertained by the ancient
authorities of the Church—one might even say, so strongly in
contradiction to their teaching—that Christ partook of the
passover on the 14th Nisan, that he died on the 15th (not on the 14th,
as the ancients considered), that he lay in the grave on the 16th, and
rose again on the 17th. In the letter we have just mentioned,
Proterius of Alexandria openly admitted all these different points.

Some years afterwards, in 457, Victor of Aquitane, by
order of the Roman Archdeacon Hilary, endeavoured to make the Roman and
the Alexandrian calculations agree together. It has been
conjectured that subsequently Hilary, when Pope, brought Victor’s
calculation into use, in 456—that is, at the time when the cycle
of eighty-four years came to an end. In the latter cycle the new
moons were marked more accurately, and the chief differences existing
between the Latin and Greek calculations disappeared; so that the
Easter of the Latins generally coincided with that of Alexandria, or
was only a very little removed from it. In cases when the
ιδ' fell on a Saturday,
Victor did not wish to decide whether Easter should be celebrated the
next day, as the Alexandrians did, or should be postponed for a
week. He indicates both dates in his table, and leaves the Pope
to decide what was to be done in each separate case. Even after
Victor’s calculations, there still remained great differences in
the manner of fixing the celebration of Easter; and it was Dionysius
the Less who first completely overcame them, by giving to the Latins a
paschal table having as its basis the cycle of nineteen years.
This cycle perfectly corresponded to that of Alexandria, and thus
established that harmony which had been so long sought in vain.
He showed the advantages of his calculation so strongly, that it was
admitted by Rome and by the whole of Italy; whilst almost the whole of
Gaul remained faithful to Victor’s canon, and Great Britain still
held the cycle of eighty-four years, a little improved by Sulpicius
Severus. When the Heptarchy was evangelized by the Roman
missionaries, the new converts accepted the calculation of Dionysius,
whilst the ancient Churches of Wales held fast their old
tradition. From this arose the well-known British dissensions
about the celebration of Easter, which were transplanted by Columban
into Gaul. In 729, the majority of the ancient British Churches
accepted the cycle of nineteen years. It had before been
introduced into Spain, immediately after the conversion of
Reccared. Finally, under Charles the Great, the cycle of nineteen
years triumphed over all opposition; and thus the whole of Christendom
was united, for the Quartodecimans had gradually disappeared.114114 It is curious that
after all the attempts that have been made to get this matter settled,
the Church is still separated into East and West—the latter
having accepted the Gregorian Calendar from which the Eastern Church,
still using the Julian Calendar, differs in being twelve days
behind. And even in the West we have succeeded in breaking the
spirit of the Nicene decree, for in 1825 the Christian Easter coincided
with the Jewish Passover!

114 It is curious that
after all the attempts that have been made to get this matter settled,
the Church is still separated into East and West—the latter
having accepted the Gregorian Calendar from which the Eastern Church,
still using the Julian Calendar, differs in being twelve days
behind. And even in the West we have succeeded in breaking the
spirit of the Nicene decree, for in 1825 the Christian Easter coincided
with the Jewish Passover!